Real-Time Performance Research Of Embedded System In Industrial Control Field

In the field of industry control, real-time performance of the system should be put to an extremely important position to be considered. Both periodic tasks such as information acquisition, control, data communication and aperiodic tasks such as arising from arbitrary critical events must be completed within their deadlines.As an excellent embedded edition of standard Linux, uClinux is especially designed for micro-control field. For the reason of not developing with the consideration of real-time performance, uClinux needs to improve its real-time capability. The introduction of embedded system with real-time consideration to industry control field should have very broad application space. This technology should be viewed as the development trend for industry control field in the future and should be the foundation stone for the company which is searching for new round of development.For the reasons gives above, this paper uses MCF5307 as the kernel to build the system hardware platform, uses Metrowerks CodeWarrior IDE as the development tool to build Bootloader program. After porting and resizing uClinux, the paper implements JFFS file system, compares several methods of reprogramming flash memory, designs monitoring program, and basically fulfills the system's requirements.For the lack of real-time capability, this paper analyzes standard Linux kernel through three aspect: processor scheduler, process scheduler, kernel timer, summering its four primary shortcomings: non-preemptive kernel, critical section turn off interrupts, soft real-time process scheduler arithmetic, and timer roughness.After compare four typical Linux real-time solutions' realization methods, basic principles, source code open degree and price etc.;choose RTAI (Real-Time Application Interface) solution. The paper detailedly analyzes the realization fundamentals of RTAI through two aspects - RTHAL and RTAI function modules.The paper researches the way of porting RTAI and application program to the MCF5307 platform. System real-time performance is improved by the means of optimizing device access time and designing device scheduler. Using logic analyzer LA-2124 to construct testing platform, writing test programs for periodic and aperiodic tasks, test results show that uClinux & RTAI solution's performance is excellent and it is very suitable for the application occasions with high real-time requirements in industry control field.Finally, on the basis of summarization of the research work, some problems which should be discussed deeply are put forward and some suggestions for the future research are also given.